Device for releasing an initial electric ignition of the propellant charge of cartridges for hand firearms

ABSTRACT

The device comprises a manually controlled impact producing member which operates a piezo-electric voltage generator which produces a sufficiently high voltage adapted to ignite the detonator of the propellant charge of the cartridge by conducting the generated voltage to an electrode in the detonator. The munition adapted to be ignited by the mentioned device comprises a projectile, a propellant charge, and a detonator composition arranged in a recess in one end of the propellant charge. The detonator comprises two axially aligned parts having, lockingly secured between the same, a cap-shaped electrode of conductive lacquer and having a flange engaging flush with the end face of the propellant charge.

States Patent [191 [4 1 Jan. 14,1975

[ DEVICE FOR RELEASING AN INITIAL ELECTRIC IGNITION OF THE PROPELLANTCHARGE OF CARTRIDGES FOR HAND FIREARMS [75] Inventor: Otto Pecksen,Herrenalb, Germany [73] Assignee: Mauser-Werke Aktiengesellschaft,

Oberndorf/Neckar, Germany 22 Filed: Sept. 16, 1971 211 App]. No.:181,276

[30] Foreign Application Priority Data Oct. 3, 1970 Germany 2048743 [52]US. Cl 42/84, 89/28 A, 102/46, 102/702 GA, 102/DIG. 1

[51] Int. Cl F4lc 19/12, F4lf 13/08, F42b 5/08 [58] Field of Search.....42/84; 89/28 R, 28 A, 28 C;

102/DIG. 1, 46, 70.2 GA

[56] References Cited UNITED STATES PATENTS 3,198,074 8/1965 Perkins42/84 3,208,181 9/1965 Calhoun et a1. 42/84 3,563,177 2/1971 Ritchey42/84 3,608,492 9/1971 Mitchell 102/46 Primary ExaminerBenjamin A.Borchelt Assistant ExaminerC. T. Jordan Attorney, Agent, or Firm-McGlew& Tuttle [57] ABSTRACT The device comprises a manually controlled impactproducing member which operates a piezo-electric voltage generator whichproduces a sufficiently high voltage adapted to ignite the detonator ofthe propel lant charge of the cartridge by conducting the gener' atedvoltage to an electrode in the detonator.

The munition adapted to be ignited by the mentioned device comprises aprojectile, a propellant charge, and a detonator composition arranged ina recess in one end of the propellant charge. The detonator comprisestwo axially aligned parts having, lockingly secured between the same, acap-shaped electrode of conductive lacquer and having a flange engagingflush with the end face of the propellant charge.

12 Claims, 10 Drawing Figures PATENIEUJANI4|975 3859.746 sum 10$ 5 I NVEN TOR.

BY 01%? Perkse WIXQOMR PM A TTGP/VEIS DEVICE FOR RELEASING AN INITIALELECTRIC IGNITION OF THE PROPELLANT CHARGE OF CARTRIDGES FOR HANDFIREARMS FIELD OF THE INVENTION The invention relates to a device forthe release of an initial electric ignition for the propellant charge ofcartridges, particularly for automatic hand firearms and machine gunsand munition adapted for the same, particularly sleeveless munition. Thedevice comprises substantially a piezo-electric voltage generatorassociated with circuit components which produce a contactfree ignitionof a detonator composition arranged in a cartridge propellant charge bygenerating the required ignition voltage upon release of a strikingphysical mass acting on the piezo-plates of a generator, the ignitionvoltage being conducted to an electrode arranged in the detonatorcomposition.

BACKGROUND OF THE INVENTION Munitions of the conventional type inautomatic band firearms and machine guns are ordinarily ignited in thata metallic primer installed in the bottom wall of the cartridge, uponactuation of the firing trigger, is acted on by a striker mass subjectedto the action of a spring. The initial ignition produced in this mannerleads to the burning of the propellent located in the cartridge casing.The gases produced during the burning of the propellent and actingprincipally on the bottom wall of the projectile drive the projectilewith increasing speed from the barrel of the firearm, which impartsguidance and direction to the projectile.

Not onlyby the inertia of the striker mass but also the mechanicaldeformation produced by the striker upon actuating the firing triggerand other unavoidable necessary mechanical operations cause quiteappreciable periods of delay prior to the release of the projectile.

It is believed to be obvious, particularly with automatic hand firearmsand machine guns, that in addition to a high starting speed v,,, thecadence required by the troops in view of the sum of unavoidable delayperiods could not be optimally made use of.

For preventing, or at least for reducing, such deficiencies anddisadvantages, it is already known to provide machine guns, for examplerapidly firing guns, with a device for the electrical ignition of themunition. The firing voltage necessary for the ignition of the munitionis furnished by a voltage source, such as a battery or a transformer.

SUMMARY OF THE INVENTION In addition to a more efficient device for therelease of an initial ignition, it is also an object of the invention toprovide a munition to be used with the ignition device of the invention,particularly a munition of sleeveless type.

In accordance with the invention, the voltage U I 2,800 V required forthe ignition of the detonator composition is reached approximately at t=6.8 7.0 usec. after the physical mass has engaged the piezo-plates of agenerator, and the ignition period up to a complete burning of thecartridge propellant charge is less than 100 psec.

According to another object of the invention, the electrical componentsassociated with the piezoelectric voltage generator comprise essentiallya conventional diode circuit with a relatively high back resistance,which upon operation of the generator effects the charging of acondenser connected in parallel to the generator.

As the function of the firearm or the firearm system is not onlydependent on the ignition device, but in equal measure also on theadequate construction of the munition to be ignited by it, particularvalue was also placed on its proper construction. The invention,therefore, requires the use of a munition-particularly a jacketlessmunition-which consists essentially of a projectile, a propellentreceiving the same-such as a compressed powder charge or the like-and adetonator composition, primer or the like, arranged in the end of thepropellent facing away from the projectile.

In accordance with the invention, the detonator composition isconstructed of multiple parts, preferably of two parts, whereby theindividual parts in the longitudi nal axis of the cartridge are pressedtogether by interposing therebetween a cap-shaped electrode which ispositively locked into the propellent.

In addition, in accordance with the invention, a flange of the electrodeis disposed flush against the surface of the propellent facing away fromthe projectile.

In order to insure a safe and positive contact of the electrode-evenunder extreme conditions-between the two detonator compositions, theelectrode is made preferably of conductive lacquer or the like.

Furthermore, the invention provides also a definite dimensioning of thetwo parts of the detonator composition in which the first part of thedetonator composition disposed next to the projectile with respect tothe second part of the detonator composition has a height or axiallength of approximately a ratio of two-thirds to one-third.

Finally, the invention indicates to an expert that the recess in thepropellant used for the reception of the parts of the detonatorcomposition, as well as the electrode, is made so deep that itprovidesin addition to the reception of an additional paper covering orthe likestill a space having an axial dimension of the order ofapproximately 0.1 0.12 mm for the transfer of the ignition voltage Ufrom the generator to the electrode.

The advantages of the invention which are believed to be obvious andconvincing are as follows:

The ignition device in its electrical and mechanical construction,according to the invention, is simple and reliable in operation. Beyondthis, the device requires little space, which to a particular degreemakes it especially adaptable to be utilized in firearms or firearmsystems.

The generation of the ignition voltage takes place in a relativelysimple, and above all in a wear-resistant, manner by employing arelatively small physical mass which strikes the piezo-plates with asuitable speed, and it is possible to generate a voltage peak of theorder of size of about 3,000 V within a rise time of less than 10 usec.This voltage peak is sufficient to insure a reliable electric initialignition of the detonator composition.

A particular advantage of employing this type of ignition device and thecorrespondingly formed munition resides in a noticeable reduction in theignition delay periods, as the detonator composition-on account of itsheight or axial length and the sharp rise in the ignition voltage-burnssubstantially more rapidly than in the conventional ignition methods,the latter of which require a relatively large time period for bringingabout the deformation of the metallic primer when the firing pin strikesthe primer housing and which also operate with lower ignition voltagesat relatively high currents. Of substantial advantage is also that withjacketless munition, the detonator composition may be provided in simplemanner with an electrode of conductive lacquer or the like. This againhas the advantage that the detonator composition requires no mechanicalcontact at all through the ignition voltage, so that the ignition takesplace not only without contact, but also the tolerance of the munitionmay be selected more liberally.

A further decisive advantage of the invention, when compared with theknown electric primers of metal, consists in that the detonatorcomposition does not lie between two electrodes which have a capacitydisposed in parallel to the resistance of the detonator composition ofabout 30 60 pF. As this capacity is capable of being charged, it is thelarger, the larger is the resistance of the detonator composition. Thismens that, with the known electric primers, the danger increases onaccount of higher voltages. It is therefore necessary with the knownelectric primers in the first place to keep the electric resistance ofthe primer small, and in the second place to short-circuit theelectrodes by means of metal foils. Apart from the fact that, with thepressed detonator composition of the jacketless munition, according tothe invention, only one electrode is required, there is also no capacityconnected in parallel to the detonator-composition resistance. Themunition to be ignited with the ignition device of the invention isadditionally far less dangerous and can readily be stored in awarehouse. Of course, on account of these especially positivecharacteristics, also the packing of the munition according to theinvention is more simple and accordingly less expensive.

Still another important advantage of the invention is an increase in thereliability of accuracy of fire. The deviations in target or aim withthe firing when using the ignition device according to the invention,are far less than with the conventional release by means of a firing pinsystem.

For an understanding of the principles of the invention, reference ismade to the following description of typical embodiments thereof asillustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings illustrate by way ofexample an embodiment of the invention.

IN THE DRAWINGS:

FIG. 1 illustrates diagrammatically and in section an ignition device inaccordance with the invention.

FIG. 2 shows a diagram in which the course of the voltage U V isillustrated in relation to the time t 11sec.

FIG. 3 is a diagrammatic illustration of a part of jacketless munition.

FIG. 4 is a diagrammatic illustration in section of a detonatorcomposition pressed into the compressed powder charge according to FIG.3 and also iliustraates the associated counterelectrode.

FIG. 5 illustrates a circuit arrangement of one embodiment of theinvention.

FIG. 6 illustrates the graph of the voltage course of the embodiment ofFIG. 5.

FIGS. 7 and 9 illustrate additional circuit arrangements of theinvention; and

FIGS. 8 and 10 illustrate the voltage courses of the modifications shownin the FIGS. 7 and 9, respectively.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the rear of anot-illustrated cartridge chamber of an automatic hand firearm ormachine gun is arranged, according to FIG. 1, a tubular housing 1coaxially to the axis of the bore. This housing 1 takes the place of amechanically operating firing pin device and is used for receiving, onthe cartridge chamber side, an anvil 2, which is provided with spacedparallel bores 2a, 2b. The anvil 2 is followed by the superimposedpiezoplates 3a connected in series so as to form a voltage generator 3.This voltage generator 3 is connected with not illustratedcompnents'comprising substantially a diode circuit, known per se, with arelatively high back resistance as well as of a correspondinglydimensioned condenser connected in parallel with the generator 3.

The-last piezo-plate 3a facing away from the anvil 2 is in suitablemanner provided with a metallic abutment counterpiece 4 on which animpact member 5 engages strikingly for causing ignition. The impactmember 5 is provided with a reduced axial extension 5a, which partiallyextends through the lower end of the tubular housing 1. Within thehousing 1 the reduced extension 5a is coaxially surrounded by a helicalimpact spring 6. The end of the extension 5a projecting from the housing1 has an annular groove 5b in which a lug 7a of a tension-and-releaselever 7 engages, which latter is pivotally supported between its endsat8 outside the housing 1.

For the release of an initial ignition in the detonator composition 11,which will be described further in detail herebelow, thetension-and-release lever is pivotally actuated in clockwise directionas indicated by the arrow in FIG. 1. When this is done, the lung 7aleaves the annular groove 5b and the physical mass formed by the impactmember 5 and its extension 5a is accelerated by the pressure of thepretensioned impact spring 6 strikingly toward the cartridge chamber.During this operation, the impact member 5 encounters the counterpiece 4connected with the piezo-plates 3a. The voltage induced during thisoperation in the piezo-plates 3a charges a condenser. The impact takingplace within 1 6.8 7.0 asec. of the voltage peak produced by the mass ofthe impact member 5 and its extension 5a of U 2,800 V ignites then thedetonator composition 11.

The diagram illustrated in FIG. 2 indicates the course of the voltage Ujust described as a function of time I in 11sec.

FIG. 3 illustrates a part of a jacketless munition. The projectile 9 ispressed into the propellent 10 consisting, for example, of a compressedpowder charge. In the lower end 10a of the compressed charge 10 facingaway from the projectile 9 is arranged a central recess 10b for thereception of the detonator composition indicated in its entirety by 11,as well as of the electrode 12 and the paper covering 13 or the likewhich usually is required.

The last mentioned details are illustrated once more in FIG. 4 on anenlarged scale, wherein particularly the cap-shaped electrode 12 isshown which consists of conductive lacquer or the like. An outwardlyextending flange on the cap-shaped electrode 12 engages flush the bottomor end face of the compressed charge 10. The detonator compositioncomprises two parts lla,

11b, while the paper covering 13 is spaced from the lower end of thespace in the cap electrode 12 a distance 14 of the order of size ofabout 0.1 0.2 mm. This distance is sufficient for the transfer of theignition voltage U, from the generator 3 to the electrode 12.

According to the circuit arrangement of FIG. 5, the voltage generator 3acts directly on the detonator composition 11 of the sleevelessmunition. The impact force P which is produced by the spring 6 causesthe generator to generate a very high voltage U, which is higher than3,000 V. This voltage is generated in the usec. range as indicated inFIG. 6. As a result of the high volltage, the spark coming from theelectrode 15 penetrates the air gap 14 and the detonator composition lllup to the counterelectrode 12. The spark produces such an amount of heatthat the entire detonator composition 11 is ignited. This has theadvantage that the detonator composition 11 of the sleeveless munitionis ignited contactless. The layer between the electrode 15 and thecounterelectrode 12 has to be of such a high ohmic value that theproduced spark develops sufficient heat from the electrode to thecounter electrode so as to cause an ignition of the detonatorcomposition l1.

FIGS. 7 and 9 illustrate circuit arrangements employing rectifiers andcondensers in addition to the circuitry shown in FIG. 5, with FIGS. 8and 10 illustrating the voltage courses of the embodiments of theinvention shown in FIGS. 7 and 9, respectively.

Referring to FIG. 7, a rectifier 26 is arranged between the detonatorcomposition 11 and the voltage generator 3. After the condenser 27 hasbeen charged by a high voltage the same operation takes place aspreviously described in connection with the FIGS. 5 and 6.

FIG. 8 illustrates a graph of the charging course of the condenser 27.

FIG. 9 illustrates a circuit employing a full wave rectifier 28 and acondenser 29, and further illustrates the impact force P and the impactrelief -P. Condenser 29 is charged to a double value as compared withthe condenser 27 of FIG. 7, so that FIG. 9 represents a condenservoltage doubling circuit.

The charging characteristic of the condenser 9, resulting in chargingthereof to double the value of the condenser 27 of FIG. 9, isillustrated in FIG. 10.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

What is claimed is:

1. In a firearm constructed and arranged for firing cartridges eachincluding a projectile, a propellant charge for the projectile, adetonator charge, for detonating the propellant charge, and saiddetonator charge having an electrode therein: a device for electricallyigniting the detonator charge by applying a high potential voltage tosuch electrode comprising, in combination, a tubular housing; an anvilat one end of said housing, a piezo-electric voltage generator mountedin said housing and having one end engaging said anvil; manuallyreleasable impact-producingmeans engaging the opposite end of saidpiezo-electric voltage generator and having a portion projecting fromsaid housing; means engaging said projecting portion of saidimpactproducing means and operable to tension and release saidimpact-producing means to impact said piezo' electric voltage generator;and circuit means connecting said piezo-electric voltage generator tothe electrode in the detonator charge of a cartridge in said firearm;said piezo-electric voltage generator, when subjected to said impact bysaid impact-producing means, generating, in substantially 6.8 to 7microseconds after impact, a voltage of substantially 2,800 Voltsapplied to said circuit means and sufficient to ignite said detonatorcharge to burn in a period of not more than microseconds to detonatesaid propellant charge.

2. Device according to claim 1, in which each cartridge comprises aprojectile, a propellant charge of compressed powder for saidprojectile, and a detonator charge arranged in the end of the propellantcharge facing away from the porjectile, said detonator charge consistingof several parts arranged in axial alignment, and a cap-shaped electrodebetween two of said parts and pressed lockingly into said propellantcharge.

3. Device according to claim 1, in which said electrode is provided witha flange disposed flat against the end face of the propellant chargefacing away from the projectile.

4. Device according to claim 1, in which said electrode consists ofconductive lacquer.

5. Device according to claim 1 in which said detonator charge comprisestwo parts of which the first part closest to the projectile has withrespect to the second part an axial dimension of approximately a ratioof twothirds one-third.

6. Device according to claim 1, in which the propellant charge isprovided with a recess for receiving the detonator charge parts as wellas said electrode, said recess being dimensioned so deep that itpermits, in addition to the insertion therein of an additional papercover, the formation of a space having an axial dimension of about 0.10.12 mm for the transfer of the ignition voltage from the piezo-electricgenerator to the electrode.

7. Device according to claim 1, in which said circuit means is a diodecircuit having a relatively high back resistance; said circuit beingconnected with said piezoelectric generator; and a condenser connectedin parallel with said generator in said diode circuit, said diodecircuit charging said condenser.

8. Device according to claim l, in which said circuit means comprises avoltage doubler circuit including a full wave rectifier having inputterminals connected in parallel to said piezo-electric generator and acondenser connected across its output terminals; said full waverectifier charging said condenser to double the value of the voltageoutput of said piezo-electric generator; one output terminal of saidfull wave rectifier being connected to said electrode and the otheroutput terminal thereof defining, with said electrode, an air gap.

9. Device according to claim 8 characterized in that said electrodearranged in the detonator-charge is substantially cap-shaped.

10. Device according to claim 9 characterized in that a cap flange ofsaid electrode lies in a plane on the surface of said propellant-chargefacing away from the projectile.

11. Device according to claim 10 characterized in that said electrodeconsists of conducting lacquer.

12. Device according to claim 8 characterized in that the air gap forthe transfer of the ignition voltage to said electrode is approximately0.1 to 0.12 mm.

1. In a firearm constructed and arranged for firing cartridges eachincluding a projectile, a propellant charge for the projectile, adetonator charge, for detonating the propellant charge, and saiddetonator charge having an electrode therein: a device for electricallyigniting the detonator charge by applying a high potential voltage tosuch electrode comprising, in combination, a tubular housing; an anvilat one end of said housing, a piezo-electric voltage generator mountedin said housing and having one end engaging said anvil; manuallyreleasable impact-producing means engaging the opposite end of saidpiezo-electric voltage generator and having a portion projecting fromsaid housing; means engaging said projecting portion of saidimpact-producing means and operable to tension and release saidimpact-producing means to impact said piezoelectric voltage generator;and circuit means connecting said piezo-electric voltage generator tothe electrode in the detonator charge of a cartridge in said firearm;said piezoelectric voltage generator, when subjected to said impact bysaid impact-producing means, generating, in substantially 6.8 to 7microseconds after impact, a voltage of substantially 2,800 Voltsapplied to said circuit means and sufficient to ignite said detonatorcharge to burn in a period of not more than 100 microseconds to detonatesaid propellant charge.
 2. Device according to claim 1, in which eachcartridge comprises a projectile, a propellant charge of compressedpowder for said projectile, and a detonator charge arranged in the endof the propellant charge facing away from the porjectile, said detonatorcharge consisting of several parts arranged in axial alignment, and acap-shaped electrode between two of said parts and pressed lockinglyinto said propellant charge.
 3. Device according to claim 1, in whichsaid electrode is provided with a flange disposed flat against the endface of the propellant charge facing away from the projectile.
 4. Deviceaccording to claim 1, in which said electrode consists of conductivelacquer.
 5. Device according to claim 1 in which said detonator chargecomprises two parts of which the first part closest to the projectilehas with respect to the second part an axial dimension of approximatelya ratio of two-thirds : one-third.
 6. DeVice according to claim 1, inwhich the propellant charge is provided with a recess for receiving thedetonator charge parts as well as said electrode, said recess beingdimensioned so deep that it permits, in addition to the insertiontherein of an additional paper cover, the formation of a space having anaxial dimension of about 0.1 - 0.12 mm for the transfer of the ignitionvoltage from the piezo-electric generator to the electrode.
 7. Deviceaccording to claim 1, in which said circuit means is a diode circuithaving a relatively high back resistance; said circuit being connectedwith said piezo-electric generator; and a condenser connected inparallel with said generator in said diode circuit, said diode circuitcharging said condenser.
 8. Device according to claim 1, in which saidcircuit means comprises a voltage doubler circuit including a full waverectifier having input terminals connected in parallel to saidpiezo-electric generator and a condenser connected across its outputterminals; said full wave rectifier charging said condenser to doublethe value of the voltage output of said piezo-electric generator; oneoutput terminal of said full wave rectifier being connected to saidelectrode and the other output terminal thereof defining, with saidelectrode, an air gap.
 9. Device according to claim 8 characterized inthat said electrode arranged in the detonator-charge is substantiallycap-shaped.
 10. Device according to claim 9 characterized in that a capflange of said electrode lies in a plane on the surface of saidpropellant-charge facing away from the projectile.
 11. Device accordingto claim 10 characterized in that said electrode consists of conductinglacquer.
 12. Device according to claim 8 characterized in that the airgap for the transfer of the ignition voltage to said electrode isapproximately 0.1 to 0.12 mm.